523 Ilvl Mage just came back, which spec?

So I just recently started playing with my mage again, and started gearing him in LFR/Flex. I was wondering which spec I should play atm for the most dps. So far I have tried fire with not so much success (100-150k Single) and I was wondering if Arcane or Frost would be better, I know how to play both of them pretty well.

However, with better gear you can choose between Fire & Arcane.. not too much difference there (In my opinion Fire slightly better for progress but need 2 good trinkets and 4set; Arcane may pull higher numbers on farm bosses)

with that ilvl probably frost..... if oyu get better gear with mastery arcane is good... fire with crit gear and frost still stays at good dps with haste......
You will probably do best dps with the spec you can handle the best!
most people say frost is the most easiest.... bust good snapshoting your bombs make a difference...
You can really play every specc in SoO as long as you don't want to max your dmg the most.... in this case you would need to respecc/forge/gem every fight.... In most cases you'll be doing faily goo with frost/arca dual as both speccs profit from haste/mastery the most.... I think it is fun to use a 2nd specc every few bosses...